Bestseller George (With No One as Witness ) departs from the usual investigative nuts and bolts of her Thomas Lynley and Barbara Havers mystery thrillers with this searing examination of the lives of one horribly dysfunctional family and their immigrant London milieu. Switching uncomfortably at times from dialogue in a rough patois to exposition in a language both formal and sociological, George delivers a stinging indictment of a society unable to respond effectively to the needs of its poorer citizens. Kendra Osborne, a 40-year-old woman with modest ambitions and plans to achieve them, has no idea how to cope when her mother "dumps" her sister's three children on her doorstep and heads for Jamaica. Fifteen-year-old Ness, 11-year-old Joel and seven-year-old Toby each have a wealth of problems exacerbated by their mixed-race heritage. It's no accident that George refers to Dickens on the first page of this earnest but perhaps overly didactic novel, which focuses on the burdens borne by Joel as he's swept by forces he can neither understand nor control into a fatal encounter. 8-city author tour. (Oct.)